Bathroom selfies, photos of restaurant menus, children playing in the yard, baby bumps — celebrities are putting their personal lives into the public domain at an unprecedented rate.

Fans can't seem to get enough. Neither can their stalkers.

In December alone, a man took a bus from Texas and waltzed into Kris Jenner’s home office where she was working. A 19-year-old from Kansas made his way cross-country to in pursuit of Lana Del Rey, breaking into her Malibu garage and boldly tweeting about it. A 27-year-old woman waited for Chris Brown’s electric gate to open before driving onto his property and refusing to leave.

And authorities are now urging Kylie Jenner to obtain a restraining order against an obsessed fan for repeatedly trying to breach her gated community in recent weeks.

“That is just the nature of the beast,” said Los Angeles Police Detective Jeff Dunn, a 31-year veteran who heads the department’s Threat Management Unit, which was established in 1990 to deal with the influx of stalkers to Hollywood. “We do our best to try to educate victims, but from the celebrity standpoint, they have to put themselves out there to their fans. That is their career.”

Social media popularity has become a major barometer used by Hollywood execs and corporate sponsors during the casting process. Keenly aware of the competition, stars are using intimate peekaboos to grow their base of followers and keep them engaged. But those peeks are also feeding another beast: the legions of obsessed fans, many of whom have mental disorders that lead them down the path of stalking.

It’s a risky calculus, but the level of social media engagement can often be the key to landing acting roles or securing lucrative business deals.

“It is almost at the nucleus of everything that is being considered,” Ryan Schinman, founder of Platinum Rye Entertainment, one of the top talent brokerage firms in Los Angeles, told BuzzFeed News. “Social prowess is a huge determining factor. If someone just blows them away in their social following, they are probably going to get the job.”

Only top box office A-listers like Tom Cruise, Sandra Bullock, or Jennifer Lawrence can afford to opt out. Most others are bound by a new set of rules: Promote, engage, and invigorate your social fanbase or else.

“In many cases, mandatory social promotion is now included in a movie contract,” said Jo Piazza, author of Celebrity, Inc.: How Famous People Make Money. “Almost every tweet or post you read has a motive. Either they are doing it to be paid by a brand, to receive something for free, or to make themselves seem more accessible in order to breed that intimacy. Everything a celebrity is posting will serve to make them money in some way.”

MANAGING THE THREAT

When LAPD Detective Mary Lopez started at the Threat Management Unit 16 years ago, threats came primarily through the mail, but now more than 90% of her cases are internet related. In 2008, celebrity stalkers were only 10% of the unit’s caseload. That has now doubled.

Part of the problem is a naïve grasp of social media on the part of celebrities, Lopez said. She recalled one actress who was shocked after flowers from a stalker showed up at her hotel room. She wanted to know how her location could have been discovered in such short order.

“I held up her Twitter and it wasn’t until that moment that she realized that she had told them,” Lopez said. “To them they are just tweeting. You don’t know who you are communicating with. You don’t know their mental stability. You have very obsessed people out there who want to be with you, and now you just communicated with them. You just made their obsession bigger.”

Experts say the obsession is driven in large part by a diagnosable condition: erotomania. They typically suffer from schizophrenia, clinical bipolar disorder, and manic depression and believe their “relationship” with a celebrity is reciprocated via a “like,” follow back, or, worse, a direct mention on social media.

“From a celebrity’s perspective, they are doing something they do hundreds of times a day, but for the fan to get a personal response from the celebrity could be the most monumental thing that has ever happened,” Reid Meloy, a forensic psychologist, told BuzzFeed News. “And a lot of times, celebrities forget that. They forget the power of just the notion of fame.”

The more serious problems begin when the fan, euphoric from a direct or perceived interaction online, feels like they’re being ignored, Meloy said.

That’s when the admiration turns.

“Then they become very angry,” Meloy said. “That starts with rejection, because they are not getting the response again.”

In years past, an obsessed fan who felt slighted posed less of a problem — the path from obsession to stalking required much more sleuthing, shoe leather, time, and effort. Now, through the power of social media, these fans have unfettered access to their celebrity targets — what their home looks like and where they eat, live, and go on vacation.

Kris Mohandie, a forensic psychologist who works closely with the LAPD, said obsessed fans with mental illnesses can also be cutthroat and target third parties they perceive as getting in their way of their celebrity match. Common personality traits include extreme determination and resourcefulness.

THE CASE OF ZACHARY BENTON SELF

Austin Valenca told BuzzFeed News he had a ringside seat to Zachary Benton Self’s unraveling.

“That kid could do anything with a camera and a computer — absolute whiz kid,” Valenca said of his high school friend. “We have always had great aspirations to become famous through our hobbies, but never managed to make it past our local scene.”

Self had been making videos since the fourth grade, when his father taught him production. By the time he was 19, he was into motorcycles, cars, and music, and had dreams of going to film school.

But somehow, Self took a wrong turn in March and was arrested in a local park for possession of marijuana, according to court records. He was ordered to pay a fine, and a few months later, he told friends he wanted to get his life on track.

Self had a job at a graphic arts studio and was working on a film project with a friend about attention deficit disorder.

“He wanted to get away from his past and start fresh,” Self’s friend Taylor Gang told BuzzFeed News.

Then one day, Self fell apart.

Valenca said his friend started rambling about how he had been touched by God and suddenly knew how the universe worked.

“He said he could control fire and make people do things against their will,” Valenca said.

It’s also when Self started talking incessantly about Lana Del Rey, saying she was leaving him breadcrumbs in her music and on social media posts. He changed his “about” section on Facebook to say, “#Engaged to Heaven on Earth #with @LanaDelRey.” He meticulously analyzed her social media and would tell Valenca how the singer’s messages were directed at him because of their spiritual connection.

Self broadcast his devotion to Del Rey on Twitter, Facebook, and Snapchat, even as those he knew joked about it behind his back. Then, without telling anyone, Self disappeared and began a pilgrimage across the country to Del Rey’s Malibu house.

On Nov. 28, he posted a message to Facebook with a map of the border between Nevada and California: “So close.” The next day, he posted a photo of the book The Satanic Witch with the caption “Thanks for leaving me a good read at the crib that’s my witch.”

The book was in Del Rey’s garage.

On Nov. 30, construction workers reporting seeing Self at Del Rey’s Malibu house, which was undergoing renovations, but by the time police arrived, he had run off. However, in his rush to escape, authorities say Self left behind his computer and all the notes about his devotion to Del Rey. The next day, sheriff’s deputies arrested Self at a nearby Starbucks, and he was charged with two felonies: stalking and first-degree burglary. If convicted, he faces nearly seven years in prison.

SEA CHANGE

The growing obsession with Hollywood’s elite fills Wendy Segall’s court calendar.

As the lead Los Angeles County deputy district attorney in charge of prosecuting high-profile celebrity-stalking cases, she’s seen how deeply the prongs of delusion can run, even when confronted with the reality of a courtroom.

“It’s just so delusional,” Segall said. “Or they believe that if the victim just sees them they will have this connection. They just have to meet and they will get to know each other.”

But that meeting can prove deadly, as was illustrated by the shocking shooting death in 1989 that sparked the creation of L.A.’s anti-stalking units. A 19-year-old fan incensed that My Sister Sam actress Rebecca Schaeffer appeared in a heated love scene onscreen traveled to Los Angeles to fatally shoot her as she answered her front door.

Segall is currently prosecuting Joshua Corbett, who broke into Sandra Bullock’s home in 2014, forcing her to barricade herself in a bedroom closet and call 911. In a recording of the call, Bullock can be heard breathing heavily and telling the 911 operator, "I'm in my closet. I have a safe door. I'm locked in the closet right now."

Corbett was arrested at the scene and charged with 19 felonies involving the possession of assault guns and other weapons, an arsenal of which was discovered in his car and home.

The case served as a chilling reminder of just how dangerous obsessed stalkers can be, but local police resources can only go so far.

Dunn, who heads LAPD’s Threat Management Unit, said he tries to keep the caseload manageable for detectives due in large part to the relentless nature of the suspects — according to the Department of Justice, 11% of stalking victims have been pursued for five or more years.

Over that time, the frequency of unwanted contacts varies. The Journal of Forensic Sciences reported that two-thirds of stalkers pursue their victims at least once per week, and 46% of stalking victims experience at least one unwanted contact per week. Even so, arrests in California can’t be made until there is a “credible threat with the intent to place a person in reasonable fear for his or her safety.” As a consequence, LAPD detectives can end up managing the same stalker for years.

But for every high-profile stalking case that hits the media, Dunn said there are 10 to 15 that his Threat Management Unit handles quietly, due in large part by early intervention and direct contact. Detectives have dropped in on stalkers mailing out their own “fantasy” wedding invitations or sitting at their celebrity’s favorite coffee shop — locations that targets frequently broadcast on Twitter. But instead of hauling the suspects off to jail, the LAPD makes its initial approach with psychologists who can immediately evaluate the situation and follow up with periodic welfare checks.

Segall likens the approach to a sort of homicide prevention. Under current law, a first-time offender can be sentenced to prison for up to three years.

“At least we can stop something before it happens,” she said. “We don’t know the behavior of these people and we don’t know what they are going to do.”

CATCH-22

For all the potential danger celebrities expose themselves to by revealing more of their personal lives, more often than not, they’re not even controlling the content, let alone interacting with fans.

Celebrities like Britney Spears, Justin Bieber, and Kim Kardashian are not sitting at their computers spending their days responding to fans and trying to grow their base of followers — “not even a little bit,” said Piazza, the author of Celebrity, Inc.

“The majority of celebrities will never touch their own social accounts,” she told BuzzFeed News.

Instead, many celebrities have their own social media manager on staff making a six-figure salary. And if the social ecosystem is too large for one person, a new niche industry has popped up to provide young teams of social media super users who respond, retweet, and like fan posts, while at the same time helping to craft carefully choreographed Instagram and Facebook posts.

Having an engaged base of followers is key, and an important factor for corporate sponsors and studio executives looking to maximize their investment in someone with a built-in, devoted fanbase.

“When a birthday is coming up, we try to like and comment on as many posts as we can, instead of doing a big video sent out to everyone,” said Lisa Jammal, who runs Social Intelligence Agency, which specializes in managing social accounts. “We know that the engagement is important. It’s beyond important. That is what is going to build your fanbase. They become more loyal to you.”